Equilibrium Practice Quiz
(30 points - self graded)

GIVEN: K_P = K_c(RT)^Δn
R= 8.31 J/(mole K)  = 0.0821 Latm/(mole K)
& a calculator.
Time yourself and write down how many minutes you spend. Aim for less than  20 minutes.

1. Hydrogen cyanide decomposes according to the following reaction:

2HCN(g)   ⇄    C₂N₂(g)   +   H₂(g)

At a certain temperature, K_P = 0.17. An experiment is started with the partial pressure of 0.45 atm for HCN and 0.32 atm for each of the other gases.

a) Calculate Q. State in which direction the reaction would proceed to reach equilibrium.(5 points)

b) Calculate the equilibrium partial pressures of all the gases. (10 points)

2. K_c = 0.0490 at 700.0 ºC for the reaction
SO₃(g)  ⇄   SO₂(g)   +   ½ O₂(g)

a) Calculate K_P for the reaction at this temperature. (5 points)

b) Calculate K_c at this temperature for the reaction (5 points)
2SO₂(g)   +   O₂(g)   ⇄     2SO₃(g)

3. Consider the reaction C(s)  +  O₂(g)   ⇄   CO₂(g)
How will each of the following changes affect the equilibrium? Briefly explain. (2.5 points each)
a) Some O₂ gas is removed.

b) Some carbon is added.

Check your answers